Flip-chip mounting is frequently employed in terms of recent demands for downsizing and cost reduction. The flip-chip mounting uses bumps to connect a device chip and a substrate. In some cases, chip components such as inductors and capacitors are additionally connected to the substrate to form electronic components as a module, so that the integration density can be improved.
Electronic component modules as described above have a problem that the functions of the device chips may be damaged due to external shock, adhesion of foreign particles, and entering water. Particularly, in a case where the device chip includes a surface acoustic wave (SAW) device or a film-bulk acoustic resonator (FBAR), the performance may be changed adversely. A specific technique of sealing and protecting the device chips is used to suppress the above problem.
Japanese Laid-Open Patent Publication Nos. 2002-76832 and 2002-84155 disclose arrangements in which acoustic wave devices and surface mounting components are mounted on a multilayer substrate, and each of the parts is sealed with sidewalls and a lid.